Random coincidence of $2\nu2\beta$ decay events as a background source in bolometric $0\nu2\beta$ decay experiments

TL;DR

This paper investigates how random coincidences of two-neutrino double beta decay events can create a background in bolometric experiments searching for neutrinoless double beta decay, and discusses methods to suppress this background.

Contribution

It analyzes the impact of $2 u2eta$ decay coincidences as a background in bolometric detectors and evaluates the potential for current technologies to mitigate this issue.

Findings

Current bolometric detectors can control this background level.

Suppression techniques are feasible for exploring the inverted neutrino mass hierarchy.

The background from $2 u2eta$ coincidences is significant but manageable.

Abstract

Two neutrino double $\beta$ decay can create irremovable background even in high energy resolution detectors searching for neutrinoless double $\beta$ decay due to random coincidence of $2\nu2\beta$ events in case of poor time resolution. Possibilities to suppress this background in cryogenic scintillating bolometers are discussed. It is shown that the present bolometric detector technologies enable to control this form of background at the level required to explore the inverted hierarchy of the neutrino mass pattern, including the case of bolometers searching for the neutrinoless double $\beta$ decay of $^{100}$Mo, which is characterized by a relatively short two neutrino double $\beta$ decay half-life.